Commercial lawn mowers that are put to use on a daily basis for lawn maintenance of large tracks of land require continuous servicing in order to perform efficiently. Unlike the conventional home-owner type of lawn mower which requires relatively little servicing, the commercial machine must be lubricated periodically in order for its working parts to function normally, particularly the shaft and bearing assemblies associated with the cutting blades. Such bearing assemblies involve more than one race of bearings, often times two or more races in a spaced apart relationship in order to adequately support and bear the heavy duty drive shaft of the commercial lawn mower. In the past, however, it has been a problem to insure that such bearing assemblies are adequately lubricated, so that all the bearings in the spaced apart races are sufficiently and effectively greased for any given bearing assembly housing.